Determining Wire Size for Electric Trolley Bus Power Supply

  • Thread starter nikola-tesla
  • Start date
In summary, an appliance with a 15-amp connector requires a 15-amp circuit breaker and a 15/20-amp receptacle. The wire size is #8 copper or #6 aluminum. If the appliance has a 24-volt connector, the wire size is #12 copper. If the appliance has a 15-amp connector, the wire size is #8 copper. If the appliance has a 15-amp connector and the voltage is supplied by the outlet, the voltage must not be less than 110 volts.
  • #1
nikola-tesla
44
0
If specs on an appliance plate read ; 15 Amps, 115 Volts.
The distance from the power source to the receptacle (plug) where the appliance is going to be plugged is 230 feet, what is the wire (american wire gage) or conductor size, the thickness of the wire? Thank you.
 
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  • #2
You can check the distance you can go with this http://www.pelco.com/support/tools/wiregacalc.aspx [Broken]

EDIT: Sorry. This calculator is for 24 volt equipment only!

Regards
 
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  • #3
Typical household wiring is AWG number 12 or 14.

See if any of these of useful -

www.faa.gov/certification/aircraft/av-info/dst/43-13/Ch_11-05.doc[/URL] (open directly or save target as), which looks like it gives gauge 8 for 115 V, 240 feet, 15A - but check the Word document.

Wire gauge calculator - [url]http://www.powerstream.com/Wire_Size.htm[/url]

Electrical conductors
[url]http://www.tpub.com/content/neets/14176/index.htm[/url]
[url]http://www.tpub.com/content/neets/14176/css/14176_20.htm[/url] - Wire gauge table
 
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  • #4
nikola-tesla said:
If specs on an appliance plate read ; 15 Amps, 115 Volts.
The distance from the power source to the receptacle (plug) where the appliance is going to be plugged is 230 feet, what is the wire (american wire gage) or conductor size, the thickness of the wire? Thank you.

Use #8 copper or # 6 aluminum. If the appliance has a 15-amp connector (plug) you must use a 15-amp circuit breaker and 15/20-amp receptacle. I am not sure a 15-amp breaker or receptacle exists that will allow connection to these large wire sizes so you’ll need to pigtail with short smaller gauge wire with approved mechanical devices. I'm not sure if doing that is allowed by the electrical code. If you use aluminum, all mechanical connection points must be approved for aluminum and must be coated with anti-oxidation paste. A # 8 copper cable may have to be special ordered in some areas and will be more expensive.

Some insurance companies will not reimburse for damage if the electrical code is not followed.




...
 
  • #5
nikola-tesla said:
If specs on an appliance plate read ; 15 Amps, 115 Volts.
The distance from the power source to the receptacle (plug) where the appliance is going to be plugged is 230 feet, what is the wire (american wire gage) or conductor size, the thickness of the wire? Thank you.

USUALLY IF THE APPLIANCE IS RATED 115 VOLTS, ITS MINIMUM OPERATING VOLTAGE OR THE ACTUAL VOLTAGE MUST BE SUPPLIED BY THE OUTLET MUST NOT BE LESS THAN 110 VOLTS.

IN THIS CASE TO BE SAFE, WE MUST ALLOW A MAXIMUM VOLTAGE DROP OF 5 VOLTS IN THE CIRCUIT. TAKE A LOOK IN THE FORMULA BELOW...

VD= 2*K*I*L/ CSA

WHERE:

VD= VOLTAGE DROP
I= CURRENT
L= DISTANCE OF THE LOAD FROM THE OUTLET (IN FT)
K= 12 FOR COPPER AND 19 ALUMINUM (FOR MAXIMUM TEMP OF 75 DC)
CSA= CONDUCTOR CROSS SECTIONAL AREA IN CIRCULAR MILS.


***SUPPOSE WE USE COPPER CONDUCTOR AND WE ALLOW A MAXIMUM OF 5V MAX. VOLTAGE DROP:

5= 2*12*15*230/CSA

CSA= 82800/5

CSA= 16560 CM

FROM COMMERCIAL REFERRENCES:

15560 CM IS CLOSEST TO 16510 CM WHICH IS #8 COPPER OR 8 SQMM WIRE.

NOTE:

1. IN THIS CASE A MAXIMUM OF 5 VOLTS WAS CONSIDERED IN THE CALCULATION.

2. THIS CALCULATION IS NOT VALID FOR LARGE MOTORS. BECAUSE MOTORS DRAWS A MAXIMUM OF 7OO% TIMES ITS FULL LOAD TORQUE DEPENDING ON THE MOTOR CONTROL STARTING METHODS USED BY THE DESIGNING ENGINEER.
 
  • #6
nikola-tesla said:
If specs on an appliance plate read ; 15 Amps, 115 Volts.
The distance from the power source to the receptacle (plug) where the appliance is going to be plugged is 230 feet, what is the wire (american wire gage) or conductor size, the thickness of the wire? Thank you.

USUALLY IF THE APPLIANCE IS RATED 115 VOLTS, ITS MINIMUM OPERATING VOLTAGE OR THE ACTUAL VOLTAGE MUST BE SUPPLIED BY THE OUTLET MUST NOT BE LESS THAN 110 VOLTS.

IN THIS CASE TO BE SAFE, WE MUST ALLOW A MAXIMUM VOLTAGE DROP OF 5 VOLTS IN THE CIRCUIT. TAKE A LOOK IN THE FORMULA BELOW...

VD= 2*K*I*L/ CSA

WHERE:

VD= VOLTAGE DROP
I= CURRENT
L= DISTANCE OF THE LOAD FROM THE OUTLET (IN FT)
K= 12 FOR COPPER AND 19 ALUMINUM (FOR MAXIMUM TEMP OF 75 DC)
CSA= CONDUCTOR CROSS SECTIONAL AREA IN CIRCULAR MILS.


***SUPPOSE WE USE COPPER CONDUCTOR AND WE ALLOW A MAXIMUM OF 5V MAX. VOLTAGE DROP:

5= 2*12*15*230/CSA

CSA= 82800/5

CSA= 16560 CM

FROM COMMERCIAL REFERRENCES:

15560 CM IS CLOSEST TO 16510 CM WHICH IS #8 COPPER OR 8 SQMM WIRE.


THEREFORE: USE #8 OR 8.0 sqmm WIRE.


NOTE:

1. IN THIS CASE A MAXIMUM OF 5 VOLTS WAS CONSIDERED IN THE CALCULATION.

2. THIS CALCULATION IS NOT VALID FOR LARGE MOTORS. BECAUSE MOTORS DRAWS A MAXIMUM OF 7OO% TIMES ITS FULL LOAD TORQUE DEPENDING ON THE MOTOR CONTROL STARTING METHODS USED BY THE DESIGNING ENGINEER.
 
  • #7
Thanks to all of you, I got it now.
 
  • #8
Hai
Iam rias iam doing my project on electric trolley bus which should be taking power supply from over head grid supply and running the vehicle through drive motors. In this case iam having various Ac & Dc voltages.
I need how to calculate the proper wire size in sqmm. please reply me as soon as possible with proper formulas. I have calculated all the terms as volt,amps,watt,res, ohms etc


Regards
A.Riaz ahamed
 

1. What is the purpose of calculating wire-conductor size?

Calculating wire-conductor size is important for determining the appropriate size of wire to use in an electrical circuit. The size of the wire affects the amount of current it can safely carry, so it is crucial to choose the right size to prevent overheating and potential hazards.

2. How do I calculate the wire-conductor size?

The wire-conductor size can be calculated using a mathematical formula that takes into account factors such as the amount of current, the length of the wire, and the material of the wire. Alternatively, there are also online calculators and charts available to help determine the appropriate wire size.

3. What factors should I consider when calculating wire-conductor size?

Aside from the amount of current and length of the wire, it is important to also consider the type of circuit and the environment in which the wire will be used. For example, outdoor or high-temperature applications may require a larger wire size to handle the heat and potential corrosion.

4. Can I use a wire with a smaller size than what is calculated?

No, it is not recommended to use a wire with a smaller size than what is calculated. This can lead to overheating and potential hazards. It is always safer to use a wire with a larger size than what is calculated, as it can handle more current and provide a margin of safety.

5. How often should I recalculate the wire-conductor size?

The wire-conductor size should be recalculated whenever there are changes to the circuit, such as adding more components or increasing the length of the wire. It is also recommended to recalculate every few years to ensure the wire size is still appropriate and meets any updated safety codes.

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